Quantification of Protozoa and Viruses from Small Water Volumes.

Large sample volumes are traditionally required for the analysis of waterborne pathogens. The need for large volumes greatly limits the number of samples that can be processed. The aims of this study were to compare extraction and detection procedures for quantifying protozoan parasites and viruses from small volumes of marine water.

Daily measures of microbes and human health at a non-point source marine beach.

Studies evaluating the relationship between microbes and human health at non-point source beaches are necessary for establishing criteria which would protect public health while minimizing economic burdens. The objective of this study was to evaluate water quality and daily cumulative health effects (gastrointestinal, skin, and respiratory illnesses) for bathers at a non-point source subtropical marine recreational beach in order to better understand the inter-relationships between these factors and hence improve monitoring and pollution prevention techniques. Daily composite samples were collected, during the Oceans and Human Health Beach Exposure Assessment and Characterization Health Epidemiologic Study conducted in Miami (Florida, USA) at a non-point source beach, and analyzed for several pathogens, microbial source tracking markers, indicator microbes, and environmental parameters.

Quantification of human polyomaviruses JC Virus and BK Virus by TaqMan quantitative PCR and comparison to other water quality indicators in water and fecal samples.

In the United States, total maximum daily load standards for bodies of water that do not meet bacterial water quality standards are set by each state. The presence of human polyomaviruses (HPyVs) can be used as an indicator of human-associated sewage pollution in these waters. We have developed and optimized a TaqMan quantitative PCR (QPCR) assay based on the conserved T antigen to both quantify and simultaneously detect two HPyVs; JC virus and BK virus.

Pathogen and indicator organism reduction through secondary effluent filtration: implications for reclaimed water production.

The reduction of pathogens and indicator organisms through secondary effluent filtration was investigated at six full-scale treatment facilities, ranging in capacity from 0.04 to 1 m3/s (1 to 25 mgd). Grab samples were assayed for pathogens (cultivable enteric viruses, Giardia, and Cryptosporidium) and indicator organisms (coliforms, enterococci, Clostridium perfringens, and coliphages) quarterly under peak flow conditions from each facility over the course of 1 calendar year.

Detection of human-derived fecal pollution in environmental waters by use of a PCR-based human polyomavirus assay.

Regulatory agencies mandate the use of fecal coliforms, Escherichia coli or Enterococcus spp., as microbial indicators of recreational water quality. These indicators of fecal pollution do not identify the specific sources of pollution and at times underestimate health risks associated with recreational water use.

Microbial source tracking by DNA sequence analysis of the Escherichia coli malate dehydrogenase gene.

Criteria for sub-typing of microbial organisms by DNA sequencing proposed by Olive and Bean were applied to several genes in Escherichia coli to identify targets for the development of microbial source tracking assays. Based on the aforementioned criteria, the icd (isocitrate dehydrogenase), and putP (proline permease) genes were excluded as potential targets due to their high rates of horizontal gene transfer; the rrs (16S rRNA) gene was excluded as a target due to the presence of multiple gene copies, with different sequences in a single genome. Based on the above criteria, the mdh (malate dehydrogenase) gene was selected as a target for development of a microbial source tracking assay.

Validity of the indicator organism paradigm for pathogen reduction in reclaimed water and public health protection.

The validity of using indicator organisms (total and fecal coliforms, enterococci, Clostridium perfringens, and F-specific coliphages) to predict the presence or absence of pathogens (infectious enteric viruses, Cryptosporidium, and Giardia) was tested at six wastewater reclamation facilities. Multiple samplings conducted at each facility over a 1-year period. Larger sample volumes for indicators (0.

Potential use of a host associated molecular marker in Enterococcus faecium as an index of human fecal pollution.

Several genotypic and phenotypic microbial source tracking (MST) methods have been proposed and utilized to differentiate groups of microorganisms, usually indicator organisms, for the purpose of tracking sources of fecal pollution. Targeting of host-specific microorganisms is one of the approaches currently being tested. These methods are useful as they circumvent the need to isolate individual microorganisms and do not require the establishment of reference databases.

Presence, infectivity, and stability of enteric viruses in seawater: relationship to marine water quality in the Florida Keys.

Concerns about the presence of enteric viruses in the surface waters of the Florida Keys prompted analyses of virus stability and persistence in these waters. In an in vitro study we evaluated the survival of poliovirus and stability of viral RNA in filtered natural seawater (FSW), unfiltered natural seawater (USW), artificial seawater (ASW) and DI water. This study compared cell culture infectivity with direct reverse transcription-polymerase chain reaction analysis.

Reduction of poliovirus 1, bacteriophages, Salmonella montevideo, and Escherichia coli O157:H7 on strawberries by physical and disinfectant washes.

The efficacy levels of different physical and chemical washing treatments in the reduction of viral and bacterial pathogens from inoculated strawberries were evaluated. Escherichia coli O157:H7, Salmonella Montevideo, poliovirus 1, and the bacteriophages PRD1, phiX174, and MS2 were used as model and surrogate organisms. Chemicals readily available to producers and/or consumers were evaluated as antimicrobial additives for the production of washes.

Geographical variation in ribotype profiles of Escherichia coli isolates from humans, swine, poultry, beef, and dairy cattle in Florida.

Waters impacted by fecal pollution can exact high risks to human health and can result in financial losses due to closures of water systems used for recreation and for harvesting seafood. Identifying the sources of fecal pollution in water is paramount in assessing the potential human health risks involved as well as in assessing necessary remedial action. Recently, various researchers have used the ribotyping method to identify sources of bacterial indicators (Escherichia coli and enterococci) in environmental waters.

Improved method for recovery of bacteriophage from large volumes of water using negatively charged microporous filters.

Current virus-recovery procedures using negatively charged microporous filters provide an inexpensive, reliable method for the recovery and detection of enteroviruses from water and wastewater; however, adjustment of the test samples to pH 3.5 to promote enterovirus adsorption results in significant inactivation of bacteriophage and an inability to simultaneously recover them from large volumes of water using this procedure. Procedures specifically designed for the detection of bacteriophage are currently in use but generally are only effective for small volumes of water.